The present invention relates generally to graphics production techniques and more particularly to an optimized technique for correcting for the effects due to lens distortion.
Previous techniques developed for inserting registered (aligned with the content of the video) graphics into a streaming video feed is based on rendering and processing the add-on graphics on the broadcaster""s side. These techniques are typically targeted towards sports broadcasts and use a combination of camera tracking and object tracking technologies. In order to insert add-graphics registered to the content of a streaming video feed, the effects due lens distortion have to be accounted for. Large amounts of data manipulation is required for such registered add-on graphic insertion, and this amount of computation is prohibitively large for processing downstream on the consumer-level hardware. There is a need for an optimized technique for distortion correction required for registered add-on graphics that can be implemented on the consumer-level hardware.
Briefly, one aspect of the present invention is embodied in an optimized method and apparatus for correcting for distortions in rendering add-on graphics within a streaming video feed comprising receiving a streaming video feed captured using a real camera, including an image frame capturing an image of a real asset having a size and a position within the image frame, the image frame being captured from a particular view point and having a particular field of view, the real camera introducing a plurality of measurable image distortions into the image frame, receiving set of camera instrumentation sensors data corresponding to the view point, the field of view, distortion parameters of the real camera, creating a virtual camera, generating add-on graphics having a size and an insertion position within the image frame, creating a first distortion grid having a first set of coordinate values, creating a second distortion grid having a second set of coordinate values wherein the second set of coordinate values are derived from the first set of coordinate values, using the second grid to distort the add-on graphics for image distortion, and compositing the distorted add-on graphics with the image frame.
The advantages of the present invention will become apparent to those skilled in the art upon a reading of the following descriptions and study of the various figures of the drawings.